An internal National Security Agency memo offers the most detailed public account yet of how former contractor Edward Snowden obtained access to the agency’s vast database of secrets. The memo, provided to members of Congress and obtained by NBC News, lends support to reports that Snowden stole a colleague’s password, something Snowden has publicly denied.

According to the memo, “at Mr. Snowden’s request, the civilian entered his PKI password at Mr. Snowden’s computer terminal. Unbeknownst to the civilian, Mr. Snowden was able to capture the password, allowing him even greater access to classified information.”

The NSA says it immediately suspended the civilian employee’s security clearance, then revoked it fully in November last year. “The civilian was not aware that Mr. Snowden intended to unlawfully disclose classified information,” the memo said. “However, by sharing his PKI certificate, he failed to comply with security obligations.” The man resigned from employment with the NSA in January.

The memo also identifies an active duty member of the military and a contractor whose access to NSA information has been restricted after they were implicated in Snowden’s actions, NBC reports No further details on their cases were offered.

The memo comes after a Reuters report that Snowden “may have persuaded between 20 and 25 fellow workers” to give him their passwords. NBC News’ report contradicts statements made by Snowden in a public chat in January, during which, responding to that accusation, he said “ the Reuters report that put this out there was simply wrong. I never stole any passwords, nor did I trick an army of co-workers.”